ipv6: addrlabel: rework ip6addrlbl_get()
If we allocate skb before the lookup, we can use RCU
without the need of ip6addrlbl_hold()
This means that the following patch can get rid of refcounting.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
index c6311d7..f314896 100644
--- a/net/ipv6/addrlabel.c
+++ b/net/ipv6/addrlabel.c
@@ -546,38 +546,28 @@
return -EINVAL;
addr = nla_data(tb[IFAL_ADDRESS]);
+ skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);
+ if (!skb)
+ return -ENOBUFS;
+
+ err = -ESRCH;
+
rcu_read_lock();
p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
- if (p && !ip6addrlbl_hold(p))
- p = NULL;
lseq = net->ipv6.ip6addrlbl_table.seq;
+ if (p)
+ err = ip6addrlbl_fill(skb, p, lseq,
+ NETLINK_CB(in_skb).portid,
+ nlh->nlmsg_seq,
+ RTM_NEWADDRLABEL, 0);
rcu_read_unlock();
- if (!p) {
- err = -ESRCH;
- goto out;
- }
-
- skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);
- if (!skb) {
- ip6addrlbl_put(p);
- return -ENOBUFS;
- }
-
- err = ip6addrlbl_fill(skb, p, lseq,
- NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
- RTM_NEWADDRLABEL, 0);
-
- ip6addrlbl_put(p);
-
if (err < 0) {
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
- goto out;
+ } else {
+ err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
}
-
- err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
-out:
return err;
}